<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>斐波那契数列</title>
</head>
<body>
    <script>
        function feibonaqi(n){
            var x = 1;
            var y = 1;

            var count = 0;
            for(var i = 0; i< n; i++){
                count = x+y;

                x=y;
                y = count;
            }
            return count;
        }
        var num = feibonaqi(4)
        console.log(num);
    </script>
</body>
</html>